Lockbolt fasteners are used extensively in the aircraft industry and elsewhere to fasten airframe and other components together. Lockbolts are employed in lieu of rivets, bolts, and other fasteners because they combine high strength with cost effectiveness.
Fasteners of the lockbolt type have a head, a shank with grooved locking rings for a collar-type retainer, and a pintail. After the fastener is installed, the collar is swaged onto that section of the fastener shank with the locking rings and the pintail of the fastener broken off, completing the fastener installation process.
Lockbolt fasteners are installed by hand starting them in previously prepared holes in the components being joined. However, because of the tight tolerances commonly found in the applications in which lockbolts are employed, friction between the fasteners and components being joined is high; greater forces than can be exerted by hand are required to seat the fasteners; and mechanical devices must be employed for that purpose.
A rivet gun is the tool commonly employed to drive into place and seat lockbolt fasteners. This, however, has a number of disadvantages. One is the noise generated by a rivet gun; a second is that the use of a rivet gun in this fashion is not compatible with the automation of assembly lines by robotics. And, lockbolt fasteners must often be installed in close enough quarters that a rivet gun cannot be used to pound on the head of the rivet.